1. Field of the Invention
The present invention relates to a multiple operation type input device capable of performing rotating operation and pushing operation, more specifically, to a multiple operation type input device suitable for use in a digital camera and the like.
2. Description of the Prior Art
In recent years, there has been widespread use of a multiple operation type input device that includes a key top arranged at the center portion of a rotatable knob (an operation body), in which, when the knob is operated rotatably, an output signal such as a resistance value can be changed, and when the key top is pushed, a push switch can be switched ON or OFF. A conventional input device of this kind is generally constructed so that the push switch is driven by pushing via the key top provided in the rotary electrical part. The rotary electrical part incorporates a slider, rotated integrally with the knob that is slidably contacted with a sliding pattern. The push switch incorporates a push switch element with a click mechanism having a movable contact and a fixed contact disposed opposite to each other. It is expected that a multiple operation type input device of compact size that can selectively perform two kinds of input operations including the rotating operation of the knob and the push operation of the key top, can be applied to various electronic devices.
The above-mentioned conventional multiple operation type input device can selectively perform two kinds of input operations including the rotating operation and the push operation. However, in the case of, for example, a digital camera with a zoom function, there is required an input device that can manage zooming with the rotating operation, and focusing and shutter operations with a two-stage push operation. The conventional multiple operation type input device cannot be applied to such an electronic device.
The present invention has been made in view of the circumstances of the prior art, and an object of the present invention is to provide a multiple operation type input device of compact size that can perform a rotating operation and a two-stage push operation and can be applied to a digital camera with a zoom function.
To achieve the foregoing object, a multiple operation type input device of the present invention comprises a rotatable operation body having an opening and self-returned to a predetermined position, a rotary electrical part driven rotatably via the operation body, a key top arranged in the opening and operated by pushing in the rotating axial direction of the operation body, and a push switch arranged at the center portion of the rotary electrical part and driven by pushing via the key top, wherein the push switch has a first push switch element and a second push switch element having different actuation forces and stacked along the push operation direction of the key top.
In the input device thus constructed, when the key top is pushed in, one of the push switch elements having a small actuating force is first switched from off to on and, when the key top is further pushed in, the other push switch element having a large actuating force is switched from OFF to ON, The input device can thus perform two-stage push operation. In addition, the operation body is rotated to change the output signal of the rotary electrical part, and upon the removal of the rotating operation force can self-return the operation body to a predetermined position. Preferably, a spring member deformed elastically with the rotation of the operation body is incorporated into the rotary electrical part, as a self-returning mechanism for self-returning the operation body.
In such a construction, preferably, the fixed contacts of the first and second push switch elements are formed on a flexible substrate and are arranged on the side of the flexible substrate nearest the key top. In particular, in a typical construction the rotary electrical part has a sliding pattern to be contacted slidably with a slider rotated integrally with the operation body. The sliding pattern and the fixed contacts of the first and second push switch elements are all formed on the common flexible substrate. It is possible to provide the multiple operation type input device that can reduce the number of parts and have good assembling properties.
In such a construction, the push switch has a driving body interposed between the first push switch element and the second push switch element for driving the second push switch element by pushing the first push switch element, guide means for guiding the movement of the driving body along the push operation direction of the key top, and click means for allowing the first and second push switch elements to each cause a click feeling at input. Since the driving body can be smoothly slide along the push operation direction of the key top, a push driving mechanism such as a hinge mechanism, which tends to be too large, is not employed, thereby easily making the device small. In this case, the guide means is provided with a plurality of guide protrusions, extending in the push operation direction of the key top, arranged so as to surround the push switch and being formed integrally with a support member for mounting the first and second push switch elements. The plurality of the guide protrusions slides the driving body more smoothly and is suitable for making the device of the present invention small.
The multiple operation type input device further comprises a guide body having the guide protrusions, a frame-like portion for coupling the base ends of the guide protrusions, and a plurality of mounting protrusions extending from the frame-like portion in the direction opposite to the guide protrusions. The mounting protrusions are mounted on the support member while the flexible substrate is held between the frame-like portion and the support member. Preferably, the flexible substrate can be prevented from being isolated from the support member. Further, each guide protrusion is formed in an elastically deformable pole shape. At its free end, the guide protrusion is provided with a nail portion capable of retaining the driving body. Preferably, the construction of the present invention must not be complicated, the driving body can be prevented from coming off, and the height position during non-operation can be defined, whereby assembling properties can be improved.
In a typical construction, the rotary electrical part has a sliding pattern to be contacted slidably with the slider rotated integrally with the operation body. The sliding pattern and the fixed contacts of the first and second push switch elements are all formed on the same surface of the flexible substrate, and the flexible substrate is bent in an S shape and is mounted on the driving body, so that the fixed contact forming region of the push switch element is arranged at the side near the key top. Preferably, it is possible to use the flexible substrate having the conductive pattern formed only on a single side, which is inexpensive and can easily be incorporated within the present invention. In this case, a pair of retaining portions is provided on the driving body, and a pair of retained portions is provided on the flexible substrate so as to be retained to the pair of retaining portions, respectively. Thus, the flexible substrate can easily be mounted on the driving body without using a double-sided adhesive sheet or the like thereby improving the assembling properties of the present invention.